ECS - EMERGING CONTAMINANTS
7) Wu, Xiaoqin, F. Ernst, J. L. Conkle, J. Gan. (2013). Comparative uptake and translocation of pharmaceuticals and personal care products (PPCPs) by common vegetables. Environment International, 60, 15-22. PDF
6) Wu, S., J. L. Conkle, J. Gan. (2012). Multi-residue determination of pharmaceutical and personal care products in vegetables. Journal of Chromatography A 1254, 78-86. PDF
5) Conkle, J. L., J Gan, M. A. Anderson (2012). Degradation and sorption of commonly detected PPCPs in wetland sediments under aerobic and anaerobic conditions. Journal of Soils and Sediments. 12(7): 1164-1173. PDF
4) Conkle, J. L., J. R. White. (2012). An initial screening of antibiotic effects on microbial respiration in wetland soils. Journal of Environmental Science and Health, Part A 47 (10): 1381-1390. PDF
3) Conkle, J. L., C. V. Lattao, J. R. White, R. L. Cook. (2010). Competitive sorption and desorption behavior for three fluoroquinolone antibiotics in a wastewater treatment wetland soil. Chemosphere 80: 1353-1359. PDF
2) Conkle, J. L., C. V. Lattao, J. R. White, R. L. Cook. (2009). Pharmaceutical analysis for environmental samples: Individual and simultaneous determination of ciprofloxacin, ofloxacin and norfloxacin using an HPLC with fluorescence and UV detection with a wetland soil matrix. Analytical Letters 42(18): 2937 - 2950. PDF
1) Conkle, J. L., J. R. White, C. D. Metcalfe. (2008). Reduction of pharmaceutically active compounds by a lagoon wetland wastewater treatment system in Southeast Louisiana. Chemosphere 73(11): 1741-1748. PDF
ECs are pollutants found in the environment where relatively little is known about their human and ecosystem health risks. ECs include many sub-categories of pollutants such as pharmaceuticals and personal care products (PPCPs), surfactants, current-use pesticides, and endocrine disrupting compounds (EDCs).
Effluents from WWTPs are the largest source of ECs in the environment. While it is unlikely that all ECs elicit a negative environmental response, hormones, endocrine disrupting compounds (EDCs) and antibiotics are perceived to pose the greatest environmental threat. Ward and Blum (2012) discovered that Bisphenol-A, a known EDC, altered the reproductive behaviors of the freshwater fish, Cyprinella. Numerous other studies have also found links between changes in fish behavior/traits or population declines and EDCs or hormones. In river systems influenced by WWTP discharge, ECs are generally <100 ng L-1, but only 5 ng L-1 of the synthetic hormone 17a-ethynylestradiol led to the collapse of fathead minnow populations in Canada's Experimental Lakes Area. Additionally, there could be hundreds of different EC compounds in WWTP discharge, prompting questions regarding the effects of compound mixtures.
Research in the C-HaWQ lab will explore the local and Gulf wide presence and ecosystem impacts of these compounds. Locally, Corpus Christi discharges treated wastewater from 6 plants that serve ~305k residents. In order to relieve stress on potable water supplies, the city is exploring the expanded use treated wastewater (aka recycled water). Currently the city diverts 2.5% of treated effluent for golf course irrigation, but has plans to increase this percentage. The city is also exploring the use of treated wastewater for managed aquifer recharge to mitigate the effects of future droughts on potable water supplies using the Corpus Christi Aquifer Storage & Recovery Conservation District. The use of treated wastewater for irrigation and aquifer recharge will introduce ECs into Corpus Christi groundwater, where studies will be needed to explore their fate and transport as well as to monitor their concentrations to assess potential public health concerns. Most of the remaining treated wastewater effluent from Corpus Christi makes its way to bays and coastal waters. While ECs have received a significant amount of attention in freshwater systems, there are large gaps in our understanding of their presence, fate and effects in coastal ecosystems that serve as vital fish spawning grounds.
The C-HaWQ lab will examine the large scale impacts of ECs in the GOM. The Mississippi River's massive flow, which contains trace concentrations of pollutants, results in the discharge of tons of individual ECs into the GOM annually. Very low concentrations of these compounds can affect aquatic organisms, but only a couple studies have explored their presence in coastal systems and to my knowledge none have examined their impacts on the economically important northern GOM fisheries. Past EC research by Dr. Conkle involved EC fate in the Mandeville, LA wastewater treatment plant (WWTP) and constructed wetland, their uptake of crops irrigated with treated wastewater and controlled lab experiments to assess sorption and degradation of individual compounds.